BurnPony

Send a secret without making the other person install anything.

Write a note, set the self-destruct rules, share one link. The note is
encrypted on your device with AES-256-GCM before anything is uploaded, and
it decrypts only in the recipient's browser. The decryption key travels in
the part of the link after the #, which browsers never send to any server —
so the server stores ciphertext it cannot read, plus a note ID, a view
count, and an expiry. No accounts, no names, no analytics.

WHAT YOU CONTROL
• Views: burn after 1 reading, or allow up to 100
• Expiry: 5 minutes to 30 days, changeable later, counted from now
• Optional passphrase, stretched with PBKDF2 and mixed into the key —
send it through a different channel than the link
• Auto-hide: the revealed note re-hides after a timer
• Read receipts, disclosed to the recipient before they reveal the note —
BurnPony does not do silent read tracking
• A private label for your own list; it never leaves your device
• QR code for in-person handoff: the whole link, key included, transfers
with no network at all

HONEST LIMITS
Whoever has the full link (and passphrase, if set) can read the note. A
recipient can always copy or photograph a note while it is visible.
Self-destruction limits future access; it does not control the moment of
reading.

OPEN
The app, the server, the viewer, and the wire-format specification are
open source (Apache-2.0), with cross-implementation test vectors shared
with the iOS app and the web viewer. Self-hosters can point the app at
their own server from Settings. Protocol: https://burnpony.app/protocol

BurnPony is part of the pony family of privacy tools: encryption you can
inspect instead of taking a developer's word for it.

---